Method of designing a multiplexing structure for resource allocation to support legacy system

This application claims the benefit of U.S. Provisional Application Ser. Nos. 61/046,779, filed on Apr. 21, 2008, 61/055,471, filed on May 23, 2008, 61/056,427, filed on May 27, 2008, and 61/056,835, filed on May 29, 2008, the contents of which are hereby incorporated by reference herein in their entirety.

This application claims the benefit of the Korean Patent Application No. 10-2009-0031268, filed on Apr. 10, 2009, which is hereby incorporated by reference as if fully set forth herein.

1. Field of the Invention

The present invention relates to a method of designing multiplexing structures for resource allocation to support legacy system, specifically relates to uplink resource unit and a distributed resource allocation method.

2. Discussion of the Background Art

The 802.16m amendment has been developed in accordance with the P802.16 project authorization request (PAR), as approved on 6 Dec. 2006, and with the Five Criteria Statement in IEEE 802.16-06/055r3. According to the PAR, the standard may be developed as an amendment to IEEE Std. 802.16. The 802.16m amendment may provide continuing support for legacy WirelessMAN-OFDMA equipment.

In a conventional IEEE 802.16e system, a basic slot structure and data region is defined as follows: a ‘slot’ in the OFDMA (Orthogonal Frequency Division Multiple Access) PHY requires both time and sub-channel dimension for completeness and serves as the minimum possible data allocation unit. The definition of an OFDMA slot depends on the OFDMA symbol structure, which varies for UL (UpLink) and DL (DownLink), for FUSC (Full Usage of Sub-Channels) and PUSC (Partial Usage of Sub-Channels), and for the distributed sub-carrier permutations and the adjacent sub-carrier permutation (AMC).

For DL FUSC and DL optional FUSC using the distributed sub-carrier permutation, one slot is one sub-channel by one OFDMA symbol. For DL PUSC using the distributed sub-carrier permutation, one slot is one sub-channel by two OFDMA symbols. For UL PUSC using either of the distributed sub-carrier permutations and for DL TUSC1 (Tile Use of Sub-Channels 1) and TUSC2, one slot is one sub-channel by three OFDMA symbols. For the adjacent sub-carrier permutation (AMC), one slot is one sub-channel by two, three, or six OFDMA symbols.

In OFDMA, a data region is a two-dimensional allocation of a group of contiguous sub-channels, in a group of contiguous OFDMA symbols. All the allocation refers to logical sub-channels. A two-dimensional allocation may be visualized as a rectangle, such as shown in FIG. 1.

In the related art, basic data allocation structures and/or pilot structures are different according to permutation rules such as PUSC, FUSC, AMC, etc. This is because permutation rules were separated in the time axis in the related art 16e system so that the structures were designed to be optimized according to each permutation rule. FIG. 2 shows an exemplary related art data allocation structure. Permutation rules are separated in time axis in the related art method. However, if more than one permutation rules exist on the same sub-frame, one unified basic data allocation structure and pilot transmission structure are required.

When multiplexing 16e system and 16m system, it is desirable to design time-frequency granularity of a PRU of a 16m system so that the PRU of the 16m system is compatible with a 16e system. In addition, it is desirable to design multiplexing structures such that performance deterioration of each of the 16e and the 16m system, which are multiplexed together, be made as low as possible.

Technical problems addressed by the present invention is in providing 16m and 16e multiplexing structures that provide optimum performance of legacy system and new systems, and in providing unified basic data allocation structure and/or pilot transmission structure.

To solve the technical problem, a novel and useful 16m and 16e multiplexing structure is provided in various forms according to the present invention. Further, a unified basic data allocation structure and/or pilot transmission structure is provided for a communication system adopting different permutation rules separated in frequency axis.

In one aspect of the invention, there is a method of communicating data between a mobile communication device and a base station. The method includes frequency multiplexing a tile of a first communication mode with a tile of a second communication mode to create a frequency multiplexed sub-frame or sub-frame group. The tile of the first communication mode comprises X₁ contiguous subcarriers and Y₁ contiguous OFDMA symbols. The tile of the second communication mode comprises X₂ contiguous subcarriers and Y₂ contiguous OFDMA symbols. X1=X2 and Y2 is a multiple of Y1.

In one aspect of the invention, the multiple is an integer multiple (e.g., 2, such that X1=X2=4, Y1=3, and Y2=6).

In one aspect of the invention, the first communication mode includes PUSC (Partial Usage of Sub-Channels) sub-channelization.

In one aspect of the invention, the second communication mode includes tile permutation.

In one aspect of the invention, the method further includes time division multiplexing the frequency multiplexed sub-frame or sub-frame group with a second sub-frame or sub-frame group of a third communication mode, where the third communication mode may include adjacent sub-carrier permutation (AMC) or distributed sub-carrier permutation.